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The objective of this study was to determine effects of room temperature and drinker design on growth and water disappearance of growing-finishing pigs (26.9 ± 3.67 to 130.9 ± 5.10 kg live body weight). A split-plot design was used with a 2 × 2 factorial arrangement of treatments: Room Temperature (RT) [Thermoneutral (TN) vs. High (HI); main plot], Drinker Design (DD; Nipple vs. Cup; sub-plot). A total of 316 pigs were used, housed in 32 pens in 4 rooms (8 pens/room; 7 pens of 10 pigs and 1 pen of 9 pigs). Two rooms were on each RT treatment. Room temperature for the TN treatment was constant throughout each day but decreased from 24°C at the start to 20°C and 18°C on d 14 and 45 of the study period, respectively. For the HI treatment, a single, cyclic RT protocol was used throughout the study (30°C from 08:00 to 19:00 h and 20°C from 20:00 to 07:00 h, with 1-h transition periods). Pens had fully-slatted concrete floors and 1 feeder and drinker (either nipple or cup); floor space was 0.67 m2/pig. Pigs had ad libitum access to standard corn-soybean diets, formulated to meet or exceed NRC (2012) nutrient requirements. Water disappearance was measured using a meter fitted to the water line supplying each drinker. There were no interactions (P > 0.05) between RT and DD treatments. Drinker Design did not affect (P > 0.05) growth performance; water disappearance was 7.3% greater (P ≤ 0.05) for Nipple than Cup drinkers. Compared to the TN treatment, the HI treatment had no effect (P > 0.05) on gain:feed ratio, but resulted in lower (P ≤ 0.05) average daily gain (6.5%) and average daily feed intake (5.5%) and greater (P ≤ 0.05) average daily water disappearance (16.8%). These results suggest that both drinker design and RT can affect water disappearance, and that the high, cyclic RT regime used reduced growth performance of growing-finishing pigs. Further research is needed to determine the contribution of water intake and wastage to treatment differences in water disappearance.

Recent increases in litter size in commercial sows have been accompanied by higher pre-weaning mortality (PWM) and lower weaning weights. The objective was to determine effects of litter size and feeding liquid milk replacer during lactation (using an automated feeder) on piglet performance. A split-plot design was used with a 2x2 factorial arrangement of treatments: Milk Replacer (MR; main plot; Unsupplemented vs. Supplemented); Litter Size [LS; sub-plot; Low (2 piglets less than functional teat number) vs. High (2 piglets greater than functional teat number)]. Cross-fostering was carried out at 24 h after birth to create treatment litters with similar gender ratio, proportion of cross-fostered piglets, and average and CV of birth weight. Milk replacer was available from 24 h after birth to weaning. Piglets were weighed on d 1 and 20 (weaning) after birth; all PWM was recorded. Growth data were analyzed using PROC MIXED of SAS; PWM data were analyzed using PROC GLIMMIX. Models accounted for fixed effects of MR, LS, the interaction, and random effects of replicate and replicate by MR interaction. There were no MR by LS interactions (P > 0.05) for any measurement. Supplemented compared with Unsupplemented litters had similar (P > 0.05) litter size at weaning and PWM, but greater (P < 0.05) average piglet and total litter weaning weight (Table 1). The High LS treatment had greater (P < 0.05) litter size and total litter weight at d 1 and weaning, but higher (P < 0.05) PWM and lower (P < 0.05) average piglet weaning weight. In conclusion, supplementing piglets with liquid milk replacer increased weaning weight with no effect on PWM, and increasing litter size above sow teat number had negative effects on both PWM and piglet weaning weight.

There is limited data available on variation in sow temperature following weaning. The objective of this study was to determine variation (diurnal and with day post-weaning) in rectal (RT) and vulva surface (VT) temperature following weaning. A cross-sectional survey was carried out using 114 multi-parous sows weaned in 7 groups between September and December. Sows were housed in individual stalls and were checked daily for standing reflex from d 4 to 8 post-weaning. Sow RT (measured with a standard thermometer) and VT (measured with an infrared thermal camera) were measured daily [at 06:15 (feeding time), 07:00, 07:30 (heat checking time), 09:00, 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00]. A repeated-measures analysis was carried out using PROC MIXED of SAS; models included the fixed effect of either study day or measurement time, and random effect of group. The number of sows exhibiting standing reflex on d 4, 5, 6, 7, and 8 post-weaning was 1, 45, 45, 19, 1, respectively; 3 sows did not exhibit standing reflex. Average VT and RT over the study period were 30.8 ± 3.23 and 38.2 ± 0.60°C, respectively; the correlation between these measurements was 0.08 (P < 0.05). There was considerable day-to-day variation in average VT (range between day: 29.5 to 32.6°C) and to a lesser extent RT (range: 37.7 to 38.5°C). The VT was higher (P < 0.05) on d 3 to 5 post-weaning compared with other days. Also, VT was higher (P < 0.05) between 06:15 and 07:30 than at the other measurement times. There was no clear pattern for either day-to-day or diurnal variation in RT. In conclusion, this study described between-sow variation in RT and VT following weaning. Further research is needed to determine if any of this variation in temperature is associated with the onset of estrus.

There is evidence that sow rectal temperature during farrowing may be associated with farrowing duration and difficulty, and stillbirth rates. However, factors affecting sow temperature during parturition have not been well quantified. The objective of this study was to evaluate relationships between sow and litter parameters and sow rectal temperature at the end of farrowing. Data (1005 sows/litters) were from 5 studies conducted on the same commercial farrowing facility with the same management. Independent variables included sow parity, use of farrowing induction, number of piglets born alive, litter weight, farrowing duration (on a sub-sample of 289 litters), and room temperature at the start of farrowing. Sow temperature at the end of farrowing averaged 38.5 ± 0.53°C. Data were analyzed using PROC REG of SAS. Models accounted for the linear, quadratic, and cubic effects of continuous independent variables, and/or the categorical effect of farrowing induction. Sow rectal temperature at the start of farrowing had a positive relationship with sow temperature at the end of farrowing and the greatest R2 value (0.33; Table 1). Individually, sow parity, farrowing duration, and induction were related (P ≤ 0.05) to sow rectal temperature at the end of farrowing. However, these factors explained a small proportion of the variation (R2 ≤ 0.05) in sow temperature. For the multivariate model, only room temperature and sow rectal temperature at the start of farrowing were related (P ≤ 0.05) to temperature at the end of farrowing, explaining 34% of the variation. In conclusion, these results suggest that sow temperature at the start of farrowing had the greatest influence on temperature at the end and that other factors (sow parity, farrowing duration, farrowing induction, and room temperature) were relatively unimportant.

This study was conducted to evaluate the water disappearance of nursery pigs (from weaning to 6 wk post-weaning; 6.4 ± 1.07 to 22.0 ± 3.39 kg live body weight) using a randomized complete block design to compare two Drinker Type treatments: Nipple vs. Cup. A total of 336 pigs housed in 16 pens with 21 pigs per pen in 2 rooms (8 pens per room) were used. Pens had fully-slatted concrete floors; floor space was 0.32 m2/pig and there was one feeder and one drinker per pen. Pigs were fed corn-soybean–based diets formulated to meet or exceed nutrient requirements. Pigs and feeders were weighed at the start and end of the study. Water disappearance was measured using a water-flow meter fitted to the water pipeline supplying the drinker in each pen. For the overall study period, Drinker Type did not affect (P > 0.05) growth performance; however, average daily water disappearance was greater (P

The objective was to evaluate associations between sow, litter, and piglet parameters and both piglet birth weight (BW), and within-litter coefficient of variation of piglet birth weight (CV). Data (1,005 sows/litters, 12,857 piglets) were from 5 studies conducted on the same commercial farrowing facility using the same management. Independent variables included sow parity, use of farrowing induction, number of piglets born alive, litter weight, BW (for analysis of CV), and piglet sex (for analysis of BW) and birth order (for analysis of BW; on a sub-sample of 289 litters/3,643 piglets). Data were analyzed using PROC REG of SAS. Models accounted for linear, quadratic, and cubic effects of each independent variable. The BW and CV averaged 1.49 ± 0.271 kg and 19.5 ± 6.69%, respectively. All independent variables were related (P ≤ 0.05) to BW (Table 1), with litter size having the strongest relationship (R2 = 0.11), and all other variables having weak relationships (R2 ≤ 0.01). All independent variables were related (P ≤ 0.05) to CV, with the exception of farrowing induction. Litter size explained the greatest amount of variation (R2 = 0.17), followed by litter weight and average piglet birth weight (R2 = 0.10 and 0.07, respectively). Other variables each explained a relatively small proportion (R2 ≤ 0.05) of variation in CV. Multivariate models including all significant (P ≤ 0.05) variables explained 13 and 22% of the variation in BW and CV, respectively. In conclusion, the primary variable associated with both BW and CV was litter size. Increases in litter size were associated with reductions in BW and increases in CV. Other variables showed weak relationships. However, even when all of these variables were accounted for, there was a large proportion of variation in both BW and CV that was not explained.

Litter sizes in commercial pig production have increased substantially over recent years; however, farrowing pen sizes have generally not changed over the same time period. The objective of this study was to evaluate the effect of farrowing pen size on piglet pre-weaning growth and mortality. Differences in pen size were created by varying the width of pens of the same length, increasing the creep area available to the piglets. The study used a total of 1,786 litters in a randomized complete block design to compare two farrowing pen size treatments (FPS): Standard (pen width 1.52 m) and Increased (pen width 1.68 m). Litter sizes were equalized across treatments (12.9 ± 1.95 piglets) at 24 h after birth using cross-fostering. Litter weights were collected at birth and weaning (21.3 ± 2.08 d); pre-weaning mortality was recorded. The experimental unit was the litter; models for statistical analysis included FPS and replicate. Farrowing pen size had no effect (P > 0.05) on litter size at birth (12.8 and 13.0 for the Standard and Increased FPS, respectively), after cross-fostering (12.9 for both treatments), or at weaning (11.2 and 11.3, respectively). There was no effect (P > 0.05) of FPS on total litter or average piglet weight at birth, after cross-fostering, and at weaning. These results suggest no benefit in piglet performance from increasing the width of farrowing pens. As litter sizes continue to increase in commercial production, further research is warranted to re-evaluate the impact of farrowing pen size on pre-weaning mortality.

Neonatal piglets can experience both a decrease in body temperature and hypoxia, increasing risks for pre-weaning mortality. This research evaluated the effects of drying and providing supplemental oxygen to newborn piglets on rectal temperature (RT) over the first 24 h after birth. The study used a CRD with three Intervention Treatments (IT; applied at birth): Control (no intervention), Drying (dried using a desiccant), Oxygen [dried using a desiccant and placed in a chamber (at 40% oxygen concentration) for 20 min]. A total of 42 litters (485 piglets) were randomly allotted to treatments at the start of farrowing. At birth, each piglet was given a numbered ear tag, weighed, and the treatment was applied; RT was measured at 0, 20, 30, 45, 60, 120, and 1440 min after birth. Blood was collected from one piglet from each birth weight quartile within each litter at 24 h after birth to measure plasma immunocrit concentration. There was no effect (P > 0.05) of IT on piglet RT at 0 or 1440 min after birth. Between 20 and 60 min after birth, piglet RT was lower (P ≤ 0.05) for the Control than the Drying treatment, with the Oxygen treatment being intermediate and different (P ≤ 0.05) from the other two IT. The effect of piglet birth weight on responses to IT were evaluated by classifying piglets into Birth Weight Categories (BWC): Light (1.5 kg). There were IT by BWC interactions (P ≤ 0.05) for piglet RT at all measurement times between 20 and 120 min after birth. Relative to the Control, the effects of the Drying and Oxygen treatments on RT were greater (P ≤ 0.05) for Light than heavier piglets. Plasma immunocrit concentrations tended (P = 0.07) to be greater for piglets on the Control treatment compared to the other two IT and were lower (P ≤ 0.05) for Light than Heavy piglets, with Medium piglets being intermediate and different (P ≤ 0.05) to the other BWC. In conclusion, drying piglets at birth reduced the extent and duration of RT decline in piglets in the early postnatal period compared to undried piglets, especially for those of low birth weight. However, the combination of drying and placing piglets in an oxygen-rich environment provided no additional benefit over drying alone.

Sow litter sizes have increased over recent decades, increasing the need for cross-fostering. The objective of this study was to determine the effect of the number of source litters used to create cross-fostered litters on piglet pre-weaning mortality (PWM) and weaning weight. A RCBD was used with 26 blocks of 5 litters (total 130 litters/1820 piglets), all litters consisted of 14 piglets. Blocking factors were farrowing day, sow parity, body condition score, and functional teat number, and the average and CV of piglet birth weight. Five cross-fostering treatments were compared: 0%, 1 source (all piglets remaining on the birth sow); 100%, 1 source (all piglets moved from birth to a different sow); 100%, 6+ sources (piglets from ≥ 6 birth sows used to form a litter on a different sow); 50%, 2 sources (7 piglets remaining with birth sow, 7 from one other sow); 50%, 4+ sources (7 piglets remaining with the birth sow, 7 from ≥ 3 other sows). The single-source litters were selected from those with > 14 piglets at birth, with excess piglets removed. For other treatments, piglets were selected to meet blocking factors. Piglets were weighed 24 h after birth and at weaning (19.5 ± 0.50 d); all PWM was recorded. Weight data were analyzed using PROC MIXED of SAS; PWM data were analyzed using PROC GLIMMIX of SAS. Models included Treatment and sow within block. There was no effect (P > 0.05) of treatment on weaning weights. Pre-weaning mortality was greater (P < 0.05) for the 0%, 1 source compared to the 50%, 2 source treatment, with the others being intermediate and generally not statistically different (Table 1). In conclusion, cross-fostering and/or mixing litters had no effect on weaning weights, but pre-weaning mortality was highest for the non-fostered treatment.

Litter sizes of commercial sows have increased recently, often resulting in the number of piglets exceeding the sow functional teat number. The objective of this study was to determine the effects of litter size after cross-fostering on piglet pre-weaning mortality (PWM) and growth. A RCBD was used with 13 blocks of 3 litters (total 39 litters/561 piglets); blocking factors were farrowing day, sow parity, body condition score, and functional teat number. Three Litter Size treatments (LS) relative to sow functional teat number were compared: Under (2 piglets below); Equal (same number of piglets); Over (2 piglets above). Piglets were weighed 24 h after birth and allotted to LS to create litters with similar gender ratio and average and CV of birth weight. Weaning was at 19.5 ± 0.50 d, weights and PWM were recorded. Piglet weight data were analyzed using PROC MIXED of SAS; PWM data were analyzed using PROC GLIMMIX of SAS. Models included LS and sow within block. Litter sizes averaged 12.1, 14.1, and 16.1 for the Under, Equal, and Over treatments, respectively (P ≤ 0.05). The Under treatment tended (P = 0.07) to have greater weaning weights compared to the Equal and Over treatments (Table 1). The Under treatment had lower (P ≤ 0.05) PWM than the Over treatment, with the Equal treatment being intermediate and not different to the other 2 (P > 0.05; Table 1). In conclusion, reducing litter size after cross-fostering to two piglets below the number of functional teats of the sow decreased PWM and tended to increase weaning weights.

Cross-fostering of piglets is a common commercial practice, however, there is limited information on optimum methods. The objective of this study was to evaluate the effects of within-litter birth weight variation after cross-fostering on piglet pre-weaning mortality (PWM) and growth. A RCBD was used with 47 blocks of 6 litters (total 282 litters/3,948 piglets); blocking factors were farrowing day, sow parity, body condition score, and functional teat number. Piglets were allotted at 24 h after birth according to Birth Weight Category (BWC) [L (< 1.0 kg), M (1.0 to 1.5 kg), or H (1.5 to 2.0 kg)] to 6 Litter Composition (LC) treatments with 14 piglets/litter: Uniform (14 L, M or H); Mixed L+M (7 L, 7 M); Mixed M+H (7 M, 7 H); Mixed L+M+H (3 L, 6 M, 5 H). Piglets were weaned at 18.7 ± 0.64 d and PWM was recorded. Piglet birth and weaning weights were analyzed using PROC MIXED of SAS; PWM were analyzed using PROC GLIMMIX of SAS; models included BWC, LC, the interaction, and sow within block. There were LC by BWC interactions (P < 0.05) for PWM and weaning weights. For L piglets, there was no effect (P > 0.05) of LC on PWM (22.8, 26.7, and 28.4% for Uniform, Mixed L+M, and Mixed L+M+H treatments, respectively). For H piglets, PWM was lower (P < 0.05) in Mixed L+M+H compared to Uniform or Mixed M+H litters (1.7, 9.6, and 5.8%, respectively). For M piglets, PWM was lower (P < 0.05) in Mixed L+M than Uniform or Mixed M+H litters (7.1, 12.2, and 14.6%, respectively); Mixed L+M+H were intermediate (10.0%; P > 0.05). Weaning weights generally followed a similar but opposite pattern for all BWC. In conclusion, increasing the average weight of littermates generally decreased weaning weights and increased PWM within each BWC.

Low blood glucose levels at the start of farrowing have been associated with increased farrowing duration and stillbirth rate. This study evaluated changes in sow blood glucose (BG) on the day of farrowing and investigated relationships between sow and litter parameters and BG. The study was carried out over 12 h from 0600h (time of last feeding) on the day sows were induced to farrow (d 115 of gestation) as a cross-sectional survey using 42 sows/gilts of which 32 farrowed. Blood samples (1.2 μL) were collected from an ear vein of each sow every 2 h from 0600 h; glucose was measured using a glucometer (Accuchek Aviva; Roche Diabetes Care, Inc., Indianapolis, IN). Sow parameters recorded included parity, body condition score (BCS: 1 = extremely thin to 5 = extremely fat), number of piglets born, total litter birth weight, and farrowing duration. Linear relationships between sow parameters and BG were developed using PROC REG of SAS. Sows that farrowed had similar (P > 0.05) BG to those that did not (84.4 vs. 86.8 mg/dL; SEM 1.76). Regression relationships between sow parameters and BG were generally weak (adjusted R2 ≤ 0.20). There was no effect (P > 0.05) of time after feeding, time after start of farrowing, or time interval between piglet births on BG. Average BG levels increased linearly (P < 0.05) with sow BCS (7.6 mg/dL/BCS; SE 2.63) but decreased linearly (P < 0.05) with sow parity (-2.5 mg/dL/litter; SE 0.96), litter size (-0.8 mg/dL/piglet; SE 0.28), litter weight (-0.06 mg/dL/kg; SE 0.26), and farrowing duration (-1.8 mg/dL/h; SE 0.82). In contrast to previous research, changes in BG from last feed to start of farrowing (which ranged from 0 to 9 h) and relationship with other sow and litter parameters were relatively limited.

Blood glucose levels in piglets at birth are potentially associated with survival, however, there has been limited research to quantify these and to establish any associations with piglet characteristics. This study, which evaluated the effects of a number of piglet characteristics on blood glucose levels at birth, was conducted as a cross-sectional survey involving 32 litters. Litter was the experimental unit; piglet was a sub-sample of litter. At birth, piglets were weighed and assigned a vitality score [1 = high vitality; 2 = low vitality (limited mobility and/or respiration)]. Piglets were then dried with a cellulose-based desiccant, and blood samples were collected from half of the piglets in each litter with a vitality score of 1 (n = 226) and all piglets with a vitality score of 2 (n = 7). Samples (1.2 μL) were collected from the vena subcutanea abdominis; blood glucose was measured using a glucometer (Accuchek Aviva; Roche Diabetes Care, Inc., Indianapolis, IN). Effects of piglet characteristics and relationships with blood glucose levels were analyzed using PROC MIXED, PROC GLIMMIX, and PROC REG of SAS, as appropriate. There were no effects (P > 0.05) of piglet birth weight or gender on blood glucose levels. Piglets with a vitality score of 2 had higher (P < 0.05) blood glucose levels than those with a score of 1. Blood glucose levels increased linearly (P < 0.05) with birth order (0.8 mg/dL for each piglet increase). In conclusion, blood glucose levels at birth were higher for piglets with low compared to high vitality and for those born later in the birth order. Further research is needed to establish relationships between blood glucose levels in piglets at birth and subsequent survival.

Piglets experience a decline in body temperature immediately after birth, and both drying and warming piglets at birth reduce this. However, these interventions may be less effective at higher farrowing room temperatures. This study was carried out at a commercial facility to compare the effect of drying and/or warming piglets at birth on postnatal rectal temperature (RT) under relatively warm farrowing room temperatures (26.6 ± 2.09 °C). Forty-five sows/litters were used in a completely randomized design to compare three Intervention Treatments (applied at birth): Control (no treatment); Warming (piglets placed in a plastic box under a heat lamp for 30 min); and Drying+Warming (piglets dried with desiccant and warmed as above). Temperatures in the warming boxes over the study period averaged 37.7 ± 2.75 °C. At birth, piglets were weighed; RT temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1,440 min after birth. Blood samples were collected at 24 h after birth from a subsample of one piglet from each birth weight quartile within each litter to measure plasma immunocrit concentration. Data were analyzed using PROC MIXED of SAS with litter as the experimental unit, and piglet as a subsample of litter. The model for analysis of piglet rectal temperature included fixed effects of Intervention Treatment, measurement time (repeated measure), the interaction, and the random effect of sow. Compared with the Control, piglet RT were higher (P ≤ 0.05) for the Warming treatment between 10 and 60 min, and higher (P ≤ 0.05) for the Drying+Warming treatment between 10 and 120 min after birth. Rectal temperatures were higher (P ≤ 0.05) for the Drying+Warming than the Warming treatment between 20 and 120 min. Responses to drying and/or warming were greater for low-birth-weight piglets ( 0.05). Immunocrit values tended (P = 0.10) to be lower for light (

Litter sizes of commercial sows have increased considerably over recent decades, and often exceed the number of functional teats on the sow. The objective of this study was to evaluate the effect of litter size after cross-fostering relative to sow functional teat number on piglet preweaning growth and mortality. A total of 39 litters (561 piglets) were used in a randomized complete block design; blocking factors were farrowing day and sow parity, body condition score, and functional teat number. Three Litter Size treatments were compared (relative to sow functional teat number): Decreased (two piglets less); Control (same number of piglets); Increased (two piglets more). Piglets were randomly allotted to treatment at 24 h after birth to form litters of the appropriate size, with similar mean and CV of birth weight within block. Weaning weights (WW) were collected at 19.5 ± 0.50 d of age; preweaning mortality (PWM) was recorded. Litter sizes were between 11 and 17 piglets, depending on block and treatment. The Decreased treatment had lower (P ≤ 0.05) PWM than the Increased (7.7% and 17.9%, respectively); the Control was intermediate (11.5%) and not different (P > 0.05) from the other treatments. The rate of decline in litter size from birth to weaning was greater (P ≤ 0.05) for the Increased than the Decreased treatment (−0.16 vs. −0.05 piglets per day), with the Control (−0.09 piglets per day) being intermediate and different (P ≤ 0.05) to the other two treatments. Litter sizes at weaning were greater (P ≤ 0.05) for the Increased than the Decreased treatment (13.3 and 11.3, respectively); the Control treatment was intermediate (12.6) and not different (P > 0.05) to the other treatments. The log odds of PWM increased with the decreasing birth weight, at a similar rate (P > 0.05) for all Litter Size treatments. However, the intercept was greater (P ≤ 0.05) for the Increased compared with the Decreased treatment; the Control was intermediate and different (P > 0.05) to the other two treatments. Mean WW tended (P = 0.07) to be greater for the Decreased (6.17 kg) compared to the Control and Increased treatments (5.86 and 5.84 kg, respectively). In conclusion, increasing litter size after cross-fostering relative to the number of functional teats of the sow increased piglet PWM, and tended to decrease WW.

Cross-fostering is a practice commonly used in the swine industry to equalize litter sizes, however, there is limited understanding of the optimum cross-fostering methods that will maximize piglet preweaning growth and survival. This study evaluated the effects of within-litter variation in birth weight after cross-fostering on piglet preweaning mortality (PWM) and weaning weight (WW) using litters of 15 piglets. A hierarchical incomplete block design was used (blocking factors: day of farrowing and sow parity, body condition score, and number of functional teats) with a 3 × 2 factorial arrangement of treatments: 1) Birth Weight Category (BWC): Light ( 0.05) PWM and WW in UNIFORM and MIXED litters. The results of this study, which involved large litter sizes typical of current commercial production, suggested that for piglet survival to weaning, using cross-fostering to form litters of piglets of similar birth weight was beneficial for light piglets, detrimental for heavy piglets, and neutral for medium piglets.

Piglets are susceptible to hypothermia early after birth, which is a major predisposing factor for preweaning mortality (PWM). Drying and warming piglets at birth has been shown to reduce early postnatal temperature decline. This study evaluated the effect of drying and warming piglets at birth on PWM and weaning weight (WW) under commercial conditions. A completely randomized design was used with 802 sows/litters (10,327 piglets); sows/litters were randomly allotted at start of farrowing to one of two Intervention Treatments (applied at birth): Control (no drying or warming); Drying+Warming (dried with a cellulose-based desiccant and placed in a box under a heat lamp for 30 min). Piglets were weighed at birth and weaning; PWM was recorded. Rectal temperature was measured at 0 and 30 min after birth on all piglets in a subsample of 10% of litters. The effect of farrowing pen temperature (FPT) on WW and PWM was evaluated by comparing litters born under COOL (1.5 kg). PROC GLIMMIX and MIXED of SAS were used to analyze mortality and other data, respectively. Litter was the experimental unit; piglet was a subsample of litter. The model included fixed effects of Intervention Treatment, and FPT or BWC as appropriate, the interaction, and the random effects of litter. Piglet rectal temperature at 30 min after birth was greater (P ≤ 0.05) for the Drying+Warming than the Control treatment (+2.33°C). Overall, there was no effect (P > 0.05) of Intervention Treatment on PWM or WW, and there were no Intervention Treatment by BWC interactions (P > 0.05) for these measurements. There was an Intervention Treatment by FPT interaction (P ≤ 0.05) for PWM. Drying and warming piglets reduced (P ≤ 0.05) PWM under COOL (by 2.4 percentage units) but not WARM FPT. In addition, WW were lower (P ≤ 0.05) under WARM (by 0.79 kg) than COOL FPT; however, there was no interaction (P > 0.05) with Intervention Treatment. In conclusion, this study suggests that drying and warming piglets at birth increases rectal temperature and may reduce PWM under cooler conditions, which are typically experienced in temperate climates during the majority of the year.

Cross-fostering is commonly used in commercial swine production to equalize litter sizes and/or adjust piglet birth weights within litters. However, there is limited published information on optimum cross-fostering procedures. This study evaluated the effects of within-litter birth weight variation after cross-fostering (using litters of 14 piglets) on piglet preweaning mortality (PWM) and weaning weight (WW). An RCBD was used (blocking factors were day of farrowing and sow parity, body condition score, and functional teat number) with an incomplete factorial arrangement of the following two treatments: 1) birth weight category (BWC): light ( 0.05) on PWM of light piglets. In conclusion, increasing the average birth weight of littermates after cross-fostering generally decreased WW and increased PWM for piglets of all birth weight categories. This implies that the optimum approach to cross-fostering that maximizes piglet preweaning growth and survival is likely to vary depending on the birth weight distribution of the population.

Piglets are born into a relatively cool environment, resulting in body heat loss, especially at low environmental temperatures. Drying and warming reduces this heat loss, but may be less effective at the higher temperatures experienced in farrowing houses in summer. This study compared the effect of warming and drying piglets at birth on post-natal rectal temperature under winter vs. summer conditions. The study was carried out at a commercial facility using a CRD with 96 sows/litters in a 2×3 factorial arrangement of treatments (applied at birth): 1) Piglet Management: Control (no treatment); Warmed (in a heated box for 30 min); Dried+Warmed (dried with desiccant and warmed); 2) Season: Winter (January-March; farrowing room temperature 21.0 ± 1.65°C); Summer (August-September; 25.3 ± 1.67°C). At birth, piglets were weighed; rectal temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1440 min after birth. Data were analyzed using PROC MIXED of SAS. Litter was the experimental unit; piglet was a subsample of litter. The model included Season, Piglet Management, and the interaction. There were treatment interactions (P < 0.05) for rectal temperatures at all measurement times except at birth. For both Seasons, the Dried+Warmed treatment resulted in greater (P < 0.05) temperatures than Warmed between 20 and 60 min; both treatments had greater (P < 0.05) temperatures than the Control between 10 and 120 min. Rectal temperatures were lower (P < 0.05) in Winter than Summer for the Control and Warmed treatments between 10 and 60 min. However, for the Dried+Warmed treatment, rectal temperatures were similar between Seasons at all times after 10 min. In conclusion, drying and warming piglets at birth was more effective for reducing rectal temperature decline than warming alone and this effect was greater in winter than summer. This research was funded by the National Pork Board.

Piglets are susceptible to chilling early after birth, which is a major pre-disposing factor for pre-weaning mortality (PWM). This study evaluated the effect of drying and warming piglets at birth on PWM at a commercial facility. A CRD was used with 802 sows (litters), allotted at start of farrowing to 2 treatments (applied at birth): Control (no treatment); Dried+Warmed (dried with a cellulose-based desiccant and warmed in a heated box for 30 min). Piglets were weighed at birth and weaning; PWM was recorded. The effects of farrowing room temperature on PWM were evaluated by classifying litters as being born under Cool or Warm conditions (< 25° C and ≥ 25°C, respectively). Similarly, effects of birth weight on PWM were evaluated by classifying piglets into 3 Birth Weight Categories (BWC; < 1.0 kg, 1.0-1.5 kg, or > 1.5 kg). PROC GLIMMIX and MIXED of SAS were used to analyze PWM and other data, respectively. Litter was the experimental unit; piglet a subsample of litter. The model included fixed effects of treatment, and farrowing room temperature or BWC as appropriate, and the random effect of piglet within litter. Rectal temperature at 30 min after birth, measured on a sub-sample of 10% of litters, was greater (P < 0.05) for the Dried+Warmed than the Control treatment. There was no effect (P > 0.05) of drying and warming piglets on weaning weight or overall PWM. Additionally, PWM was similar across treatments within each BWC. However, the Dried+Warmed treatment reduced (P < 0.05) PWM compared to the Control under Cool but not Warm farrowing room temperatures. In conclusion, this suggests that drying and warming piglets at birth increases rectal temperature and may be an effective method to reduce piglet PWM under cooler farrowing room temperatures. This research was funded by the National Pork Board.

Piglets are born wet, and evaporation of that moisture decreases body temperature, increasing the risk of mortality. The objective of this study was to compare the effect of two commercially applicable methods for drying piglets at birth on piglet rectal temperature over 24 h after birth. The study was carried out in standard commercial farrowing facilities with 52 litters, using a completely randomized design with three Drying Treatments: Control (not dried); Desiccant (dried at birth using a cellulose-based desiccant); Paper Towel (dried at birth using paper towels). Litters were randomly allotted to treatments at the birth of the first piglet. At birth, piglets were individually identified, and the treatment was applied. Rectal temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1,440 min (24 h) after birth. Data were analyzed using a repeated measures model with PROC MIXED of SAS, with litter as the experimental unit and piglet a subsample of the litter. The model included the fixed effects of treatment and time (as a repeated measure), and the interaction. There was no effect (P > 0.05) of treatment on temperature at birth, or 10 or 1,440 min after birth. Piglet temperatures between 20 and 120 min after birth were similar (P > 0.05) for the Desiccant and Paper Towel treatments, but were greater (P ≤ 0.05) than the Control. The effect of birth weight on the response to Drying Treatment was evaluated by dividing the data into Light (1.5 kg) piglet Birth Weight Categories. Piglet rectal temperature data at each measurement time were analyzed using a model that included the fixed effects of Birth Weight Category, Drying Treatment, and the interaction. Temperatures of Light piglets were lower (P ≤ 0.05) than those of Heavy piglets between 20 and 120 min after birth, with Medium piglets being intermediate and generally different to the other two weight categories at these times. The difference in temperature between Light as compared with Medium or Heavy piglets was greater for the Control than the other two Drying Treatments at 60 min after birth. These results suggest that drying piglets at birth is an effective method to reduce rectal temperature decline in the early postnatal period, especially for low birth weight piglets.

Piglets experience a rapid decrease in body temperature immediately after birth, increasing the risk of mortality. The objective of this study was to determine the effect of drying and/or warming piglets at birth on rectal temperature over the first 24 h after birth. The study was carried out at a commercial sow facility using a completely randomized design with four treatments (applied to piglets at birth): Control (no drying or warming), Desiccant (dried using a desiccant), Warming Box (placed in a box under a heat lamp for 30 min), and Desiccant + Warming Box (both dried and warmed as above). Farrowing pens had one heat lamp, temperatures under which were similar to the warming box (35 °C). A total of 68 litters (866 piglets) were randomly allotted to a treatment at the birth of the first piglet. At birth, each piglet was identified with a numbered ear tag and weighed; rectal temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1,440 min after birth. Data were analyzed using a repeated-measures model using PROC MIXED of SAS. Litter was the experimental unit, piglet was a subsample of the litter; and the model included the fixed effects of treatment, time (the repeated measure), and the interaction. Rectal temperatures at birth and 1,440 min after birth were similar (P > 0.05) for all treatments. At all times between 10 and 120 min after birth, Control piglets had lower (P ≤ 0.05) temperatures than the other three treatments. The Desiccant and Warming Box treatments had similar (P > 0.05) temperatures at most measurement times, but the Desiccant + Warming Box treatment had the highest (P ≤ 0.05) rectal temperatures at most times between 10 and 60 min. In addition, for all treatments, light (1.5 kg) piglets at all times between 10 and 120 min. In addition, at these measurement times, the deviation in temperature between the Control and the other three treatments was greater for light than medium or heavy piglets. In conclusion, both drying and warming piglets at birth significantly increased rectal temperatures between 10 and 120 min after birth, with the combination of the two interventions having the greatest effect, especially for low birth weight piglets.

Piglets often experience hypothermia early after birth. Previous research has suggested that drying piglets and administration of oxygen (a potential treatment for asphyxiation) at birth may increase post-natal rectal temperatures. The objective of this study was to determine the effects of drying and administering oxygen at birth on piglet rectal temperature over the first 24 h after birth. The study, conducted at a commercial facility, used a CRD with 42 sows/litters randomly allotted at start of farrowing to 3 treatments (applied at birth): Control (no drying or oxygenation); Dried (using a cellulose-based desiccant); Dried+Oxygen [dried and placed in a chamber (40% oxygen) for 20 min]. At birth, piglets were weighed and uniquely identified. Rectal temperature was measured at 0, 20, 30, 45, 60, 120, and 1440 min after birth. Data were analyzed using PROC MIXED of SAS. Litter was the experimental unit; piglet was a subsample of litter. The statistical model included effects of treatment, time of measurement, and the interaction. Both the Dried and Dried+Oxygen treatments had greater (P < 0.05) rectal temperatures than the Control between 20 and 120 min. However, the Dried+Oxygen treatment had lower (P < 0.05) rectal temperatures than the Dried treatment between 20 and 60 minutes. Temperatures at 1440 min were lower (P < 0.05) for the Dried+Oxygen than the other treatments; however, differences were small. In conclusion, drying piglets at birth increased rectal temperatures over the first 2 h after birth. The combination of drying piglets at birth and placement in an oxygen chamber for 20 min was less effective at moderating post-natal temperature changes than drying alone. Further research on piglet oxygenation is necessary to understand the reason for these reduced temperatures, and whether this treatment affects pre-weaning mortality. This research was funded by the National Pork Board.

There is limited understanding of optimum cross-fostering methods to use to maximize piglet performance. This study evaluated effects of within-litter birth weight variation after cross-fostering on pre-weaning piglet removals (PR; morbidity and mortality) and ADG. A hierarchical incomplete block design was used (blocking factors day of farrowing and sow parity and structure) with a 3x2 factorial arrangement of treatments: 1) Birth Weight Category (BWC): Light (< 1.0 kg), Medium (1.0-1.5 kg), or Heavy (1.5-2.0 kg); 2) Litter Composition (LC): Uniform (piglets of the same BWC), and Mixed (equal numbers of piglets from each BWC). Piglets were weighed 24 h after birth and allotted to form litters of 15 cross-fostered piglets. The experimental unit was 5 piglets of the same BWC (3 experimental units per litter). A total of 102 litters were allotted to 17 blocks of 6 litters (1 Uniform litter of each BWC; 3 Mixed litters) with 51 replicates (3 replicates/block of 6 litters). Weaning weights and PR were measured. PROC GLIMMIX and MIXED of SAS were used to analyze PR and other data, respectively. Models included BWC, LC, the interaction, and replicate within block. There were treatment interactions (P < 0.05) for all measures except birth weight. There was no effect (P > 0.05) of LC on weaning weight or ADG for Light or Medium piglets; Heavy piglets had greater (P < 0.05) weaning weight and ADG in Mixed than in Uniform litters. PR were greater (P < 0.05) for Light piglets in Mixed than in Uniform litters, and for Heavy piglets in Uniform than in Mixed litters. PR for Medium piglets were similar (P > 0.05) across LC treatments. In conclusion, rearing cross-fostered piglets in Uniform litters reduced PR for Light piglets, but increased PR and reduced ADG of Heavy piglets, with no effect for Medium piglets.

All piglets experience hypothermia immediately after birth, which can be a predisposing factor for pre-weaning mortality. Drying piglets at birth with a desiccant reduces the extent and duration of postnatal temperature decline. This study compared the effectiveness of different types of commercially-available desiccant products using a CRD with four treatments (applied at birth): Control (piglets not dried) and 3 Desiccant Product treatments [dried with a Mineral-based, Cellulose-based, or Mixed (mineral and cellulose-based) desiccant]. Sows (40) and litters (546 piglets) were randomly allotted to a treatment at the birth of the first piglet. Sows were housed in individual farrowing crates within pens; a heat lamp was suspended over one side of each pen. Room temperature was set at 22.8°C throughout farrowing. Piglets were weighed at birth, those on the Desiccant Product treatments were coated with desiccant until completely dry, and then returned to the pen. Piglet rectal temperatures were measured at 0, 15, 30, 45, 60 and 120 min after birth. Data were analyzed using PROC MIXED of SAS (SAS Inst. Inc., Cary, NC). The model included the fixed effects of treatment, measurement time (repeated measure), and the interaction. There was no effect (P > 0.05) of treatment on rectal temperatures at birth. At all other measurement times, piglets on the Control treatment had lower (P < 0.05) rectal temperatures than those on the 3 Desiccant Product treatments, which had similar (P > 0.05) rectal temperatures. These results suggest that the 3 commercial desiccant products evaluated were equally effective at minimizing the extent and duration of piglet rectal temperature decline in the early postnatal period.

Newborn piglets experience a rapid decrease in body temperature, increasing the risk of mortality. The objective of this study was to determine the effect of drying and/or warming at birth on piglet rectal temperature over 24 h after birth. The study was carried out at a commercial sow facility using a CRD with 4 treatments: Control (no drying or warming of piglets), Drying (piglets dried at birth using a cellulose-based desiccant), Warming (piglets placed in a box under a heat lamp for 30 min after birth), and Drying+Warming (piglets dried and warmed as above). Piglets were identified with a numbered ear tag. They were weighed at birth and rectal temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1440 min (24 h) after birth. Sows and litters were randomly allotted at birth to treatments. Data were analyzed using a repeated measures model with PROC MIXED of SAS. Litter was the experimental unit and piglet was a subsample of the litter; the model included the fixed effects of treatment and repeated time, and the interaction. Rectal temperature at birth was similar (P > 0.05) for all treatments. Subsequently, piglets on the Drying and Warming treatments had similar (P > 0.05) temperatures, which were greater (P 0.05) than the Control at all measurement times up to 120 min. Drying+Warming resulted in the highest (P < 0.05) rectal temperature overall and at most times of measurement between 10 and 120 min. Rectal temperatures were similar for all treatment at 24 h after birth. In conclusion, drying and/or warming piglets at birth significantly increased rectal temperatures between 10 and 120 minutes after birth with the combination of the two having the greatest effect. This research was funded by the National Pork Board.

The objective of this study was to evaluate the effects of piglet birth weight and drying piglets at birth on post-natal rectal temperatures using a CRD with 2 treatments: 1) Drying (not dried vs. dried at birth with a desiccant); 2) Birth weight [4 within-litter birth weight quartiles (Q1: 1.13 ± 0.33 kg, Q2: 1.43 ± 0.28 kg, Q3: 1.62 ± 0.28 kg, Q4: 1.81 ± 0.28 kg)]. Sows (26) and litters (281 piglets) were randomly allotted to drying treatment and were housed in farrowing crates with a heat lamp; room temperature was set at 22.8°C. Piglets were weighed at birth and rectal temperature measured at 0, 15, 30, 45, 60, 90, 120, 180, 240, and 1440 min after birth. Data were analyzed using PROC MIXED of SAS (SAS Inst. Inc., Cary, NC); the model included fixed effects of litter birth weight quartile and drying treatment and interaction, and time (repeated measure), and random effect of sow. Mean piglet birth weight and rectal temperature at birth were 1.49 ± 0.39 kg and 39.2 ± 0.43°C, respectively. There were no drying by birth weight treatment interactions. Temperatures were similar (P > 0.05) for the drying and birth weight treatments at birth and 240 and 1440 min (Table 1). Drying increased (P < 0.05) rectal temperature from 15 to 180 min; the greatest difference was at 45 min (2.4°C). Temperatures were similar (P > 0.05) for Q2, 3, and 4 from 15 to 180 min. Quartile 1 had a lower (P < 0.05) temperature than the 3 heavier quartiles from 15 to 180 min, except at 120 min when temperatures were similar for Q1 and 2. The lightest piglets exhibited the greatest post-natal temperature decline and drying of piglets at birth reduced the post-natal temperature decline in piglets of all weights.

Piglets are born wet, and evaporation of that moisture decreases body temperature, increasing the mortality risk. The objective of this study was to compare the effect of 2 commercially-applicable piglet drying methods on rectal temperature over 24 h after birth. The study was carried out at a commercial sow facility using a CRD with 3 treatments: Control (piglets not dried); Desiccant (piglets dried at birth using a cellulose-based desiccant); Paper Towel (piglets dried at birth using paper towels). Piglets were weighed at birth and individually identified with a numbered ear tag. Rectal temperature was measured at 0, 10, 20, 30, 45, 60, 120, and 1440 min (24 h) after birth. Sows and litters were randomly allotted to treatments. Data were analyzed using a repeated measures model with PROC MIXED of SAS. Litter was the experimental unit and piglet was a subsample of the litter; the model included the fixed effects of treatment and repeated time, and the interaction. There was no effect (P > 0.05) of treatment on rectal temperature at birth, or at 10 min or 24 h after birth. The Desiccant and Paper Towel treatments had greater (P < 0.05) temperatures than the Control at all times of measurement from 20 to 120 min after birth. Piglets on the Desiccant treatment had greater (P < 0.05) temperatures than those on the Paper Towel treatment between 30 and 120 min after birth. In conclusion, drying piglets at birth with either a desiccant or paper towels increases rectal temperatures between 20 and 120 minutes after birth, with the greatest effect being for the desiccant. Further research is needed to compare other methods of increasing piglet temperature and to determine if drying of piglets impacts pre-weaning mortality. This research was funded by the National Pork Board.

Pre-weaning piglet mortality (PWM) is a substantial economic loss and a welfare concern. It is not a new issue; however, there is evidence that levels are increasing in US herds. Genetic improvements in prolificacy have been accompanied with lower average piglet birth weights, increased within-litter variation in birth weight, and an increasing proportion of low birth weight piglets. Low birth weight is a major pre-disposing factor for PWM. In a survey involving over 11,000 piglets (average birth weight 1.44 ± 0.390 kg), PWM for piglets weighing 1.5 kg was 44, 15, and 8%, respectively. However, the percentage of total mortality from these 3 weight groupings was 35, 42, and 23%, respectively. This suggests that efforts to reduce PWM should mainly focus on lightest 50% of piglets in a population. The major causes and timing of PWM have not changed over time. Crushing and starvation are predominant; the majority of losses occur in the first few days after birth. A substantial proportion of dead piglets have empty stomachs. Pre-weaning mortality is multifactorial in origin; reducing levels requires attention to all factors, starting with farrowing accommodation design and basic facility hygiene programs. Minimizing piglet body temperature decline after birth, and encouraging early colostrum and milk intake are critical. Strategies to reduce competition between piglets for access to the udder and/or supplementary feeding programs are important. Cross-fostering is central to maximizing piglet survival; however, there is a dearth of research-based information to use to design the optimum strategy. The potential influence of gestation nutrition on PWM requires clarification. Pre-weaning mortality is strongly influenced by the people managing the farrowing facilities; developing approaches for early identification of at risk pigs would have benefit. Ultimately, minimizing PWM requires systems-based approaches involving all components from genetic selection for survival through to facility and animal management practices.